Caul board separator



March 29, 1960 H. A. RADDIN ETAL 2,930,078

CAUL BOARD SEPARATOR Filed May 25, 1956 4 Sheets-Sheet 1 @LSE) LSI INVEN TORJ' HARRY A RADDIN DONALD L.JOHNSON March 29, 1960 H. A. RADDIN ETAL CAUL BOARD SEPARATOR Filed May 23, 1955 4 Sheets-Sheet 2 FIG. 2

INVENTORS HARRY A. RADDIN DONALD L. JOHN SON ATfOR V March 29, 1960 H.A. RADDIN ETAL 2,930,078

CAUL BOARD SEPARATOR Filed May 23, 1956 4 Sheets-Sheet 3 FIG.3

/ INVEN TOR.

- I HARRY A- RADDIN By DONALD L.JOHNSON A T TORNEVS March 29, 1960RADDlN ETAL 2,930,078

CAUL BOARD SEPARATOB 4 Sheets-Sheet 4 Filed May 23, 1956 HU EImQQ m m mm3i n50 IN VEN TORS HARRY A. RADDIN BY DONALD L.JOHNSON fla 2,930,078Patented Mar- 29,1960:

CAUL BOARD SEPARATOR Harry A. Raddin, Richmond, Va., and Donald L.Johnson,

Tacoma, Wash., assignors, by direct and mesne assignments, to MillerHoift, Inc., Richmond, Va., a corporation of Delaware Application May23, 1956, Serial No. 586,694

3 Claims. (Cl. 18-2) It is an object of this invention to provideapparatus for removing boards molded from, a mixture .of wood chips andresin from the trays or cauls in'which such boards are molded.

is a further object of this invention to provide in an apparatus asaforesaid a system of controls for automatic operation whereby theapparatus is adapted to cooperate. with other machine elements in themanufacture of such boards.

The above and other objects will be made clear with the followingdetailed description taken in connection with the annexed drawings inwhich:

l is a plan view of the improved apparatus;

Fig. 2 is a section on the line 2-2 of Fig. 1;

Fig'. 3 is a side elevation of the improved apparatust.

4 is a detailed view of certain elements of the apparatus; and

Figs. 5A, 5B and 5C are wiring diagrams of the control circuits.

There is a rapidly growing interest in manufacture of boards from wastewood products suitably reduced to Chips or particles which are mixedwith a thermosetting binder'pressed to the desired caliper and heatedsufficiently to set the resin and thus to bind the chips together into astrong, rigid board. For various commercial reasons, such boards areproduced in an ultimate panel size of 4 by 8 feet. andin thicknessesfrom as little as A inch to as much as 1 /2 inches. 'The boards" areformed by depositing a loose layer of chips into a series of cauls whichare then inserted into a multiple platen press which operforms theheating and pressing steps above referred to.

Obviously, the loaded cauls must remain in the press for a substantialtime in order effectually to cure the thermosetting binder throughoutthe cross-section of the board, the precise time depending on the natureof the resin and the caliper of the board. Until quite recently, thissubstantial curing time was considered to limit the manufacture of theseboards to a batch type of process. All of the other steps in themanufacture of the board were susceptible of continuous consecutiveoperation. There have been devised automatic mechanisms for loading andunloading a multiple platen press and these. are designed to receiveconsecutive boards until a press load has been attained and then todeliver to or remove from the press a full charge of boards. Theunloading mechanism delivers boards consecutively in the same manner inwhich the loading mechanism receives boards.

The present invention is concerned with apparatus which receivesconsecutive loaded cauls from the press unloading mechanism, separatesthe board from the caul and delivers the empty caul for refilling.

The wiring diagrams of Figs. 5A, 5B and 5C carry NEMA symbols based onIndustrial Control ICI23.5 October 1951.

Referring now to Figs. 1, 2 and 3, there is shown a pair of ejectorbelts 10 supported by table rolls 12. Loaded cauls are delivered to thebelts 10 by a ram forming part of the press unloading mechanism. As willbe described in detail hereinafter, delivery of the caul to the belts 10starts the belts traveling in the direction of the arrow 14 shown inFig. 1. The belts are auto. matically stopped when the caul reaches apredetermined position.

When the belts stop, vacuum is applied through line 16 to a pair ofdiaphragms 18. Diaphragms 18 raise a pair of suction cups 20 intocontact with the bottom'of, a tray 24 resting on the belts 10. When thecups 20 come in contact with the bottom of the tray 24, vacuum isapplied through a line 26 to the interior of the cups 20, thus grippingcups 20 firmly to the bottom of the tray 24. With the cups thus firmlyin engagement, vacuum is applied through the line 28 to another pair ofdiaphragms 30. The diaphragms 30 over-ride to a degree the liftingaction of the diaphragms 18, thereby exerting a downward pull on thesuction cups 20 and thereby upon the trays 24.

The attainment of a predetermined vacuum in the diaphragms 30 operates aconventional four way valve (not shown) to deliver pressure or vacuum asthe case may be, to a cylinder'36. A piston within the cylinder 36 isconnected to a rod 38 which is pivoted to a rocka ble lever 40. Thecylinder 36 is itself pivoted to the machine frame at 42 and is fed orexhausted through lines 44 and 46. The lever is keyed at one end to ashaft 48 rotatable in bearings 50 secured to the machine frame. Alsokeyed to the shaft 48 and adjacent each of its ends are a pair of levers52, the free ends of which are pivoted to links 54. Each of the links 54is pivotally secured to a shaft 56. Each end of the shaft 56 is rigid lysecured to a shaft 58. Each of the shafts 58 is slidably mounted inbearings 60 secured to the machine frame. A plate 62 is rigidly securedto the front end of each of the shafts 58. A pusher plate 64 abuts onthe plate 62 and is secured there by a holding plate 66. By forming Onthe opposite side of the machine is a lower feed roll 70 and 'an upperfeed roll 72. The upper feed roll 72 is spring loaded and verticallyadjustable. When thepiston rod 38 moves forward, it rocks the shaft 48by means of the lever 40. This in turn rocks the levers 52 v which bymeans of the links 54, draws forward the shaft; 56, draws forward theshaft 58 and brings the pusher plates 64 into contact with a board 74resting in the caul 24. The board 54 is thrust into the grip of the.constantly rotating rolls 70 and 72 and is fed clear of the machinewhile the caul or tray 24 is held by the vacuum cups 20. There are twoalternative structures for removing the empty caul from the machine. Oneof these, as shown in Fig. 4, is to use a constantly running chaincarrying a series of hooks 82 which engage with loops 84 formed at theleading end of each tray. This has the advantage of providing positiveand accurate placement of the trays but as will appear hereinafter, thisarrangement adds some complication to the controls. The alternative (notshown) is simply to provide conveyer belts and deliver the empty traysby operation of the ejector belts 10.

The control system will now be described with particular reference toFigs. 5A, 5B and 5C. A loaded caul is thrust onto the belts 10 by thepress unloading mechanism and depresses first LS29 and then LS-30. Theseare limit switches which condition the press unloading mechanism for itsnext operation. Details of the circuits involved in LS29 and LS-30 formno part of this invention. Initially, the belts 10 were started bypushing either of the start buttons shown in Fig. 5B. As the caulproceeds, it depresses a limit switch LS 2 which energize a contactrelay CR-l. This stops the ejector belt and energizes a timed delayrelay TD-2. TD2,

after a delay of one or two seconds, energizes solenoid 1. Solenoid 1operates a valve to apply vacuum to the diaphragms 18 whereby to raisevacuum cups 20. The TD-2 interlock shown in Fig. A is a holding circuitto keep things going even if LS-2 should be released because of liftingof the caul by the vacuum cups 20.

When the vacuum in diaphragms 18 reaches a predetermined value, apressure switch VS--1 closes to energize a solenoid 2 which operates avalve to apply vacuum to the cups 20 through the line 26 and also toapply vacuum to diaphragms 30 through the line 28.

When the vacuum in the cups 20 and the diaphragms 30 reaches apredetermined value, a pressure switch VS-2 closes, energizing asolenoid 3. The solenoid 3 operates a four way valve to actuate thecylinder 36 and its associated linkage. When the lever 40 reaches itsforwardmost position, it closes a limit switch LS-5 which energizes arelay CR2. Energization of CR2 breaks the circuits of solenoid 1, 2 and3, which has the efiect of releasing the empty caul from the grip of thesuction cups 20.

When the chain 80, shown in Fig. 4, is in use, the timing is such thatthe lug 84 will be engaged by hook 82 and the empty caul will be drawnout of the machine. In passing, the empty caul will close limit switchesLS-l and LS-3. Limit switch LS-3 starts the ejector belts 10, while LS-lenergizes the time delay relay TD-1. After a short time delay, TD1starts the press unloading mechanism previously preconditioned by LS29and LS-30.

A limit switch LS4 is mounted on an arm 90 pivoted on the shaft 92around which the belt 80 is driven and is adjustable to variouspositions. Each hook 82 will close LS-4 just before it comes intocaulengaging position. It is as shown in Fig. 5A in the circuitof CR3.When LS-4 is closed by a hook 82, CR3 is energized, its four contactsare changed, three normally closed contacts open and one normally opencontact closes. Closing of the one normally open contact holds the CR3circuit closed even though the hook passes over to release LS-4. One ofthe normally closed contacts on opening, stops the caul-returnedconveyer by deenergizing a coil C1, another stops the ejector beltbydeenergizing a coil C2, both as shown in Fig. 5B. The third breaks thecircuit to a coil M5, which shuts down the press unloading mechanism.LS4 will energize CR3 only if the feed line L-1 of Fig. 5A is open. Theline L1 will be alive only when both the CR-1 and CR2 contacts areclosed, a condition which, as above noted, exists only during theadvance of the pusher plate 64. When the pusher plate closes LS 5 toenergize CR2, the normally closed CR2 contact, Fig. 5A, opens anddeenergizes the line L1. Therefore, if vacuum is on the cauls when LS-4is closed the system will stop, if vacuum is not on the cauls the lineL1 is dead and CR--3 will not energize when LS-4 is closed by the hook82.

The adjustment quadrant 92 shown in Fig. 4 permits ssetting of the timelag between the time 15-4 is closed and the time the hook 82 reachescaul tab 84. This is to accommodate the ditferent time cycles occasionedby diiferent thicknesses of board.

If belts are used in place of the chain and books 82, such belts runcontinuously and are similar to belts 10. The empty caul in such case isdelivered to the caulremoving conveyer by the ejector belts 10. For suchoperation, LS-S is eliminated and CR2 is used to start the ejector beltto deliver an empty caul to the empty caul conveyer.

While certain specific embodiments of this invention have been describedherein, it is clear that as a matter of design there is room forconsiderable variation of detail. Accordingly, this invention is not tobe limited to the precise details disclosed but only as set forth in thesubjoined claims.

We claim:

1. Means to separate boards formed of a mixture of wood particles andresin, pressed and cured to rigid condition from the trays in which suchboards were pressed and cured, said means comprising: a unidirectionalconveyer for loaded trays; means to stop the progress of the trays onand with said conveyer; means to grip and hold the stopped tray; meansto strip the board from the tray in a direction at right angles to themotion of the conveyer, and means responsive to the complete removal ofa board from a tray to release said gripping and holding means forfurther progress of the empty tray on and with said conveyer.

2. Means as set forth in claim 1 including a limit switch operable bypassage of an empty tray and a relay responsive to said switch forrestoring the apparatus to its original position.

3. Means as set forth in claim 1 including a hook bearing conveyer, thehooks of said conveyer being spaced to engage loops on each empty tray;and a limit switch in the path of said hooks, said limit switchoperating to disable the apparatus if said gripping and holding meansare still active.

References Cited in the file of this patent UNITED STATES PATENTS1,851,028 Worrall Mar. 29, 1932. 2,499,399 Lyon Mar. 7, 1950 2,619,681Baker et a1. Dec. 2, 1952 2,625,284 Atwood Jan. 13, 1953 2,629,158 MollaFeb. 24, 1953 2,636,625 Pries Apr. 28,1953 2,642,782 Chapman June 23,1953 2,704,608' Graf et-al Mar. 22, 1955 2,775,787 Krag Ian. 1, 1957

